TBX4 variants and pulmonary diseases:getting out of the 'Box'

Purpose of review In 2013, the association between T-Box factor 4 (TBX4) variants and pulmonary arterial hypertension (PAH) has first been described. Now - in 2020 - growing evidence is emerging indicating that TBX4 variants associate with a wide spectrum of lung disorders. Recent findings TBX4 variants are enriched in both children and adults with PAH. The clinical phenotype associated with a TBX4 variant seems to be milder than that in other PAH-associated gene mutations. Further, TBX4 variants have increasingly been associated with a variety of clinical and histopathological phenotypes, including lethal developmental parenchymal lung diseases such as not only acinar dysplasia in neonates, but also less outspoken parenchymal lung diseases in children and adults. Summary The clinical phenotype of a TBX4 variant has recently been recognised to expand from bone disorders to different types of lung diseases. Recent data suggest that variants of TBX4, a transcription factor known to be an important regulator in embryonic development, are not rare in both children and adults with PAH and/or developmental parenchymal lung diseases

Adverse drug reactions of montelukast in children and adults

Montelukast, a selective leukotriene receptor antagonist, is recommended in guidelines for the treatment of asthma in both children and adults. However, its effectiveness is debated, and recent studies have reported several adverse events such as neuropsychiatric disorders and allergic granulomatous angiitis. This study aims to obtain more insight into the safety profile of montelukast and to provide prescribing physicians with an overview of relevant adverse drug reactions in both children and adults. We retrospectively studied all adverse drug reactions on montelukast in children and adults reported to the Netherlands Pharmacovigilance Center Lareb and the WHO Global database, VigiBase((R)) until 2016. Depression was reported most frequently in the whole population to the global database VigiBase((R)) (reporting odds ratio (ROR) 6.93; 95% CI: 6.5-7.4). In the VigiBase((R)), aggression was reported the most in children (ROR, 29.77; 95% CI: 27.5-32.2). Headaches were reported the most frequently to the Dutch database (ROR, 2.26; 95% CI: 1.61-3.19). Furthermore, nightmares are often reported for both children and adults to the Dutch and the global database. Eight patients with allergic granulomatous angiitis were reported to the Dutch database and 563 patients in the VigiBase((R)). These data demonstrate that montelukast is associated with neuropsychiatric adverse drug reactions such as depression and aggression. Especially in children nightmares are reported frequently. Allergic granulomatous angiitis is also reported, a causal relationship has not been established

Failing Homeostasis of Quadriceps Muscle Energy- and pH Balance During Bicycling in a Young Patient With a Fontan Circulation

Aims: Patients with a congenital heart condition palliated with a Fontan circulation generally present with decreased exercise capacity due to impaired cardiopulmonary function. Recently, a study in patients with a Fontan circulation reported evidence for abnormal vascular endothelial function in legmuscle. We investigated if abnormal skeletal muscle hemodynamics during exercise play a role in the limited exercise tolerance of Fontan patients. If so, abnormalities in intramuscular energy metabolism would be expected both during exercise as well as during post-exercise metabolic recovery. Methods: In a young patient with a Fontan circulation and his healthy twin brother we studied the in vivo dynamics of energy-and pH-balance in quadriceps muscle during and after a maximal in-magnet bicycling exercise challenge using 31-phosphorus magnetic resonance spectroscopy. An unrelated age-matched boy was also included as independent control. Results: Quadriceps phosphocreatine (PCr) depletion during progressive exercise was more extensive in the Fontan patient than in both controls (95% vs. 80%, respectively). Importantly, it failed to reach an intermittent plateau phase observed in both controls. Quadriceps pH during exercise in the Fontan patient fell 0.3 units at low to moderate workloads, dropping to pH 6.6 at exhaustion. In both controls quadriceps acidification during exercise was absent but for the maximal workload in the twin brother (pH 6.8). Post-exercise, the rate of metabolic recovery in the Fontan patient and both controls was identical (time constant of PCr recovery 32 +/- 4, 31 +/- 2, and 28 +/- 4 s, respectively). Conclusion: Homeostasis of quadriceps energy- and pH-balance during a maximal exercise test failed in the Fontan patient in comparison to his healthy twin brother and an age-matched independent control. Post-exercise metabolic recovery was normal which does not support the contribution of significant endothelial dysfunction affecting adequate delivery of oxidative substrates to the muscle to the lower exercise capacity in this particular Fontan patient. These results suggest that mitochondrial ATP synthetic capacity of the quadriceps muscle was intact but cardiac output to the leg muscles during exercise was insufficient to meet the muscular demand for oxygen. Therefore, improving cardiac output remains the main therapeutic target to improve exercise capacity in patients with a Fontan circulation

Cardiac Magnetic Resonance Derived Left Ventricular Eccentricity Index and Right Ventricular Mass Measurements Predict Outcome in Children with Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is associated with increased right ventricular (RV) afterload, affecting RV remodeling and RV performance, a major determinant of outcome in PAH-patients. In children with PAH, treatment strategy is guided by risk stratification where noninvasive prognosticators are highly needed. The prognostic value of RV characteristics derived by cardiac magnetic resonance (CMR) has been scarcely studied in pediatric PAH. We aimed to identify CMR-derived morphometric and functional RV characteristics prognostic for outcome in children with PAH. From the Dutch National cohort, thirty-eight children with either idiopathic/heritable PAH (IPAH/HPAH) or PAH associated with congenital heart disease (PAH-CHD), who underwent CMR, were included (median (interquartile range) [IQR] age 13.0 years (10.8–15.0), 66% females). Patients had severe PAH, characterized by their World Health Organization Functional Class, increased N-terminal pro-B-type natriuretic peptide and high pulmonary arterial pressure and pulmonary vascular resistance index at time of CMR. RV-ejection fraction (RVEF), indexed RV-mass (RVMi), the ratio between RV and LV mass (RVM/LVM-ratio) and left ventricular eccentricity index (LVEI) all correlated with transplant-free survival from time of CMR. These correlations could not be confirmed in the PAH-CHD group. This study shows that CMR-derived measures reflecting RV function and remodeling (LVEI, RVMi, RVM/LVM-ratio, RVEF) predict transplant-free survival in children with IPAH/HPAH and may be included in risk stratification scores in pediatric PAH.</p

Fate of pulmonary hypertension associated with bronchopulmonary dysplasia beyond 36 weeks postmenstrual age

Objective To determine the survival and evolution of pulmonary hypertension (PH) associated with bronchopulmonary dysplasia (BPD) in extremely premature born infants beyond 36 weeks postmenstrual age (PMA). Design A single-centre retrospective cohort study from a university hospital. Patients Extremely preterm (gestational age Main outcome measures Survival, mortality rate and PH resolution. Patient characteristics, treatment, presence and evolution of PH were collected from patient charts. Results Twenty-eight infants were included. All had BPD, while 23 (82%) had severe BPD and 11 infants (39%) died. Survival rates at 1, 3 and 7 months from 36 weeks PMA were 89%, 70% and 58%, respectively. In 16 of the 17 surviving infants, PH resolved over time, with a resolution rate at 1 and 2 years corrected age of 47% and 79%, respectively. At 2.5 years corrected age, the resolution rate was 94%. Conclusions These extremely preterm born infants with PH-BPD had a survival rate of 58% at 6 months corrected age. Suprasystemic pulmonary artery pressure was associated with poor outcome. In the current study, infants surviving beyond the corrected age of 6 months showed excellent survival and resolution of PH in almost all cases. Prospective follow-up studies should investigate whether resolution of PH in these infants can be improved by multi-modal therapies, including respiratory, nutritional and cardiovascular treatments

Parenteral Prostanoids in Pediatric Pulmonary Arterial Hypertension:Start Early, Dose High, Combine

RATIONALE: There are currently no data supporting specific dosing and weaning strategies for parenteral prostanoid therapy in children with pulmonary arterial hypertension (PAH). OBJECTIVES: To describe the clinical practice of intravenous (IV) or subcutaneous (SC) prostanoid therapy in pediatric PAH and identify dosing strategies associated with favorable outcome. METHODS: From an international multicenter cohort of 275 children with PAH, 98 patients who received IV/SC prostanoid therapy were retrospectively analyzed. RESULTS: IV/SC prostanoids were given as monotherapy (20%) or combined with other PAH-targeted drugs as dual (46%) or triple therapy (34%). The median time-averaged dose was 37 ng/kg/min, ranging 2–136 ng/kg/min. During follow-up, IV/SC prostanoids were discontinued and transitioned to oral or inhaled PAH-targeted therapies in 29 patients. Time-dependent receiver operating characteristic analyses showed specific hemodynamic criteria at discontinuation of IV/SC prostanoids (mean pulmonary arterial pressure 25 ng/kg/min), early start after diagnosis, and combination with other PAH-targeted drugs were associated with better transplant-free survival. CONCLUSIONS: Early initiation of IV/SC prostanoids, higher doses of IV/SC prostanoids, and combination with additional PAH-targeted therapy were associated with favorable outcome. Transition from IV/SC prostanoid therapy to oral or inhaled therapies is safe in the long term in selected children, identified by reaching hemodynamic criteria for durable IV/SC prostanoid discontinuation while on IV/SC prostanoid therapy

Serial Measurements of N-Terminal Pro-B-Type Natriuretic Peptide Serum Level for Monitoring Pulmonary Arterial Hypertension in Children

OBJECTIVE: To assess the association between serially measured N-terminal pro-B-type natriuretic peptide (NT-proBNP) serum levels and disease severity in children with pulmonary arterial hypertension (PAH), and to assess its predictive value for death or (heart-)lung transplantation. STUDY DESIGN: This was a longitudinal cohort study of the Dutch National Network for Pediatric Pulmonary Hypertension conducted between 2003 and 2017. Data on NT-proBNP and disease severity markers (World Health Organization Functional Class [WHO-FC], 6-minute walking distance [6MWD], and tricuspid annular plane systolic excursion [TAPSE]) were collected every 3 to 6 months from 82 children with PAH. The outcome measure was death or (heart-)lung transplantation. Also, NT-proBNP levels over time were compared between survivors and nonsurvivors. RESULTS: The median patient age was 8.8 years (IQR, 4.6-13.5 years), and 61% were female. The median duration of follow-up was 4.8 years (IQR, 1.9-10.0 years). At all times during the course of disease, higher NT-proBNP levels were associated with higher WHO-FC (β = 0.526; 95% CI, 0.451-0.600), lower 6MWD z-score (β = -0.587; 95% CI, -0.828 to -0.346), lower TAPSE z-score (β = -0.783; 95% CI, -1.016 to -0.549), and elevated risk of death or (heart-)lung transplantation (hazard ratio 16.61; 95% CI, 7.81-35.33). Compared with survivors, nonsurvivors had NT-proBNP levels that were higher at first measurement and increased exponentially over time (P = .005). Changes in NT-proBNP serum level over time were predictive of outcome. CONCLUSIONS: Throughout the disease course of pediatric PAH, serial measurements of NT-proBNP are associated with disease severity and transplant-free survival. Monitoring NT-proBNP levels over time provides important prognostic information that can support clinical decision making in combination with other established prognostic markers